side_effect
1. [ noun ] (medicine) a secondary and usually adverse effect of a drug or therapy
Examples:

"severe headaches are one of the side effects of the drug"

Related terms: effect black_tongue
2. [ noun ] any adverse and unwanted secondary effect
Synonyms: fallout
Examples:

"a strategy to contain the fallout from the accounting scandal"

Related terms: consequence
Similar spelling:   side_by_side